The cpsa package

The Cryptographic Protocol Shapes Analyzer (CPSA) attempts to
enumerate all essentially different executions possible for a
cryptographic protocol. We call them the shapes of the protocol.
Naturally occurring protocols have only finitely many, indeed very
few shapes. Authentication and secrecy properties are easy to
determine from them, as are attacks and anomalies.

For each input problem, the CPSA program is given some initial
behavior, and it discovers what shapes are compatible with
it. Normally, the initial behavior is from the point of view of one
participant. The analysis reveals what the other participants must
have done, given the participant's view. The search is based on a
high-level algorithm that was claimed to be complete, i.e. every
shape can in fact be found in a finite number of steps. Further
theoretical work showed classes of executions that are not found by
the algorithm, however it also showed that every omitted execution
requires an unnatural interpretation of a protocol's roles. Hence
the algorithm is complete relative to natural role semantics.

The package contains a set of programs used to perform and display
the analysis. A standards complient browser, such as Firefox,
Safari, or Chrome, is required to display the results. Program
documentation is in the doc directory in the source distribution,
and installed in the package's data directory. You can locate the
package's data directory by typing cpsa --help to a command
prompt. New users should start learning to use the tool from the
manual, found at cpsamanual.pdf in the data directory. Examples
referenced in the manual can be found in the data directory as well.
It is suggested that users make an examples directory and copy
*.scm *.xhtml to their local examples directory, both so that
they may be modified and for ease of access.

Serious Windows users should install MSYS so as to allow the use of
make and script execution.

The theory and algorithm used by CPSA was developed with the help of
Joshua D. Guttman, John D. Ramsdell, Jon C. Herzog, Shaddin
F. Doghmi, F. Javier Thayer, Paul D. Rowe, and Moses D. Liskov.
John D. Ramsdell and Moses D. Liskov implemented the algorithm in
Haskell. CPSA was designed and implemented at The MITRE Corporation.

Downloads

Maintainer's Corner

Readme for cpsa

Readme for cpsa-3.3.2

CPSA: Cryptographic Protocol Shapes Analyzer
This program has been built and tested using Haskell Platform.
It is available from <http://haskell.org> or from an operating
system specific source. The name of the Linux package is usually
haskell-platform.
If the Internet is available, install CPSA with:
$ cabal update
$ cabal install cpsa
Find the documentation directory by typing "cpsa -h" in a command
shell, and view index.html in a browser.
INSTALLING FROM A TARBALL
QUICK START (Linux)
: To build and install CPSA type:
$ make
$ make install
: To analyze a protocol you have put in prob.scm type:
$ cpsa -o prob.txt prob.scm
$ cpsagraph -o prob.xhtml prob.txt
$ firefox -remote "openFile(`pwd`/prob.xhtml)"
: Documentation and samples are in the directory given by
$ cpsa -h
: To view the user guide:
$ firefox -remote "openFile($HOME/share/cpsa-X.Y.Z/doc/cpsauser.html)"
: where X.Y.Z is the CPSA version number.
QUICK START (Mac)
: To build and install CPSA type:
$ make
$ make install
: To analyze a protocol you have put in prob.scm type:
$ cpsa -o prob.txt prob.scm
$ cpsagraph -o prob.xhtml prob.txt
$ open prob.xhtml
: Documentation and samples are in the directory given by
$ cpsa -h
: To view the user guide:
$ open $HOME/share/cpsa-X.Y.Z/doc/cpsauser.html
: where X.Y.Z is the CPSA version number.
QUICK START (Windows)
The software has been tested on a Windows system on which neither
MinGW or Cygwin has been installed. Install GHC and then run the
"setup.bat" batch file with administrator privileges.
If you do not have administrator privileges, run:
C:\...> runghc Setup.hs configure --user
C:\...> runghc Setup.hs build
The executables will be found in the dist\build subdirectories.
Documentation and samples are in the directory given by
C:\...> cpsa -h
The installed programs can be run from the command prompt or via a
batch file. Alternatively, copy doc/Make.hs into the directory
containing your CPSA problem statements, and load it into a Haskell
interpreter. Read the source for usage instructions.
MAKEFILE
The file $HOME/share/cpsa-X.Y.Z/doc/cpsa.mk contains useful GNU Make
rules for inclusion, where X.Y.Z is CPSA version number.
Alternatively, copy the file Make.hs in the same directory into the
directory containing your CPSA problem statements. The source file
has usage instructions.
PARALLELISM
CPSA is built so it can make use of multiple processors. To make use
of more than one processor, start CPSA with a runtime flag that
specifies the number of processors to be used, such as "+RTS -N4
-RTS". The GHC documentation describes the -N option in detail.
DOCUMENTATION
The starting point for CPSA documentation doc/index.html. Most users
should read it and skip the rest of this section.
To build the documentation, the file supp-pdf.tex must be installed.
It is part of the TexLive texmf ConTeXt package. On Linux, the name
of the package is context or texlive-context. The design document and
the specification document require the xy-pic package, which is
included in texlive-pictures.
The documentation includes a user guide as an XHTML document, and
three LaTeX documents. The CPSA Primer provides the background
required to make effective use of the CPSA tool collection. For those
interested in the implementation, The CPSA Theory contains a
high-level description of the algorithm and the current state of the
effort to show that when program terminates, it produces a description
of every possible execution of the protocol consistent with the
initial point-of-view skeleton. The CPSA Specification formally
describes the implemented algorithm as a term reduction system. The
CPSA Design describes implementation details and assumes The CPSA
Specification has been read. The CPSA Design should be read if one is
interested in reading the Haskell source for the tool collection.
TEST SUITE
: To run the test suite type:
$ ./cpsatst
Tests with the .scm extension are expected to complete without error,
tests with the .lsp extension are expected to fail, and tests with the
.lisp extension are not run. New users should read tst/README, and
then browse the files it suggests while reading CPSA documentation.
Don't develop your protocols in the tst directory. The Makefile is
optimized for testing the cpsa program, not analyzing protocols.
ADDITIONAL PROGRAMS
The src directory of the source distributions includes programs
written in Scheme, Prolog, and Elisp for performing tasks. Use them
as templates for your special purpose CPSA analysis and transformation
needs. Also, when given the --json option, the CPSA pretty printer
cpsapp will transform CPSA S-expressions into JavaScript Object
Notation (JSON).
On Linux, the GHC runtime can request so much memory that thrashing
results. The script in src/ghcmemlimit sets an environment variable
that limits memory to the amount of free and reclaimable memory on
your machine.
KNOWN BUGS
Variable separation in generalization fails to separate variables in
terms of the form (ltk a a).